for number 22, it says independently, 1/3 chance of getting COVID. It has not been specified that you have to first meet a person with covid, then have a 1/3 chance of getting it, in fact since it says INDEPENDENTLY, it means it cannot depend on another factor such as the 50 percent chance of getting COVID

Hi Kevin,

You are right on both of these comments! We're very sorry for the error in the diagram not showing up. I've fixed this and it should work now. (You can also the diagrams in this printable .pdf) Thanks so much for your patience.

Thanks also for pointing out the unclear conditions in question #22. We will refine the question to indicate that we are concerned only with the probability of catching COVID from the three people in the problem.

We really appreciate your patience and for letting us know. Please tell us if you see anything else!

]]>